ignore null/undefined value
ignore null/undefined value

FlorianLudwig/gown.js,leftees/gown.js,brean/pixi_ui,brean/pixi_ui,brean/pixi_ui,leftees/gown.js,leftees/gown.js,FlorianLudwig/gown.js,leftees/gown.js,FlorianLudwig/gown.js,brean/pixi_ui,FlorianLudwig/gown.js